Field of the Invention
The present invention relates to a method of forming a stretchable substrate, a stretchable substrate, and an electronic device having a stretchable substrate.
Description of the Related Art
Recently, stretchable electronic devices have been highlighted. Those electronic devices can freely bend and curve in comparison to existing electronic devices, so an interest in the electronic devices have been increased in the fields of display and bio engineering. In the related art, since the stretchable electronic devices are formed on stretchable substrates, they are extended or compressed with extension and compression of the substrates. This is because when a physical force such as tensile, buckling or torsion force is applied to a general elastic body from the outside, the elastic body uniformly and isotropically deforms throughout the entire section.
When an external force is applied to a stretchable substrate, the stretchable substrate extends in the direction of the external force. In general, electronic circuits or wirings formed on substrates have different Young's modulus from that of the substrates, so the degree of strain of the electronic circuits or wirings due to an external force is different from that of the substrates. For example, when an electrical wiring having low stretchability is formed on a substrate having higher stretchability than the wirings, and then a tensile force is applied to the substrate, the electrical wiring that is lower in stretchability than the substrate cannot extend as much as the substrate and stress is exerted in the electrical wiring, so the electric wiring is physically damaged, such as cracking. Accordingly, an electronic or an electric device electrically connected through the electrical wiring cannot stably operate. This phenomenon may occur even when not only the electrical wiring, but another electronic device having stretchability different from that of the stretchable substrate is formed on the substrate and then an external force is applied to the substrate, so it is difficult to guarantee stable operation of the electronic devices on the stretchable substrate.